Abstract: A filter press for the thickening of cellulose pulp or sludge in which the filter press is furnished with a feedbox to lead the sludge suspension to the wire. In order to increase the capacity of filter presses or the like, the sludge to be dried can be fed through a feedbox in accordance with the invention, in which box there is at least one surface penetrating the liquid to facilitate thickening of the sludge suspension before it is lead to the filter press wire.

Abstract: Magnetic separator for the purification of liquids with a tube which conducts the latter, contains balls or wire screens as magnetizable bodies and is surrounded by a coil for magnetizing the bodies. The tube contains, in the flow direction of the liquids over the major part of its length, balls and subsequently wire screens. A common coil is associated with the balls and the wire screens for magnetizing. The balls and the wire screens are connected to a common flushing line.

Abstract: A multiple-disc filter includes a pressure member located within the filter housing upstream of the discs forming the stack to press the discs tighter together when the fluid flows from the housing inlet to the housing outlet, and to permit the discs to move apart for cleaning the filter when the fluid flows in the reverse direction. Each filter disc is formed with alternating groups of radially-extending slots to define circumferential filtering passageways between the ends of the slots.

Abstract: A cleaning system for ink jet printing orifices includes cooperative elements which provide varying pressure differentials across the orifice plate that oscillate ink into and out of the orifices. In one embodiment the pressure differentials are implemented by varying the impedance to ink cross-flow through a print head cavity while pressurizing a region around the exterior of the orifices.

Abstract: A self-cleaning renewable fluid filter that flushes a permanent filter media while the used oil is pumped out by the engine oil pump through a drain in the housing. The fluid filter has an inlet and a drain, a center core with an outlet, a drain valve normally closing the drain, a permanent fluid filter media inbetween the inlet and outlet, a plug for closing the outlet, an actuator for opening the drain valve and an improved bypass valve which bypasses fluid and enables reversal of fluid flow through the filter media during draining for flushing the media. The preferred drain valve actuator is an electric solenoid coil inside of the filter and the improved bypass valve is an annular valve around the center core and inside of a cylinder formed in an inlet end cap of the filter media.

Abstract: An apparatus (10) for use with a dry cleaning system having a filter for filtering the dirty solvent comprises a first pressure vessel (28) for vaporizing the filtered solvent and a second pressure vessel (58) for condensing the vapors into purified liquid solvent for collection and reuse. The upper end of the second pressure vessel (58) is upset to provide an annular chamber about the upper end of the condenser coil (76) which extends in closely spaced apart relationship into the reduced lower end of the second pressure vessel, so that clogging is avoided and better contact with the condenser coil and thus more complete condensation is achieved. In the preferred embodiment, the apparatus 10 includes a valve arrangement (104, 106, 108 and 118) by which the filter can be backflushed with hot fluid, such as steam in order to recover solvent from the saturated filter and render it safe for ordinary disposal.

Abstract: A separator for magnetical removal of solid particles from fluid media comprises a flow chamber filled with a rod-type ferromagnetic orienting packing, and a magnetic system for magnetizing the packing. The packing rods are arranged along the flow of the medium being purified and contact each other over lateral surfaces thereof.

Abstract: A self-cleaning filter installed in a cylindrical conduit for a liquid to be cleaned, such as cooling water for an industrial power plant, comprises a sieve spanning the conduit and undulating between an upstream and a downstream transverse plane. The interior of the conduit is divided into two or more sectoral compartments which are bounded by corresponding sieve segments on the downstream side and are provided with respective peripheral outlets leading to a drain, these outlets being normally closed by associated shutoff valves. To clean any sieve segment bounding a particular compartment, the upstream entrance to that compartment is obstructed by a flap valve while the corresponding shutoff valve is opened to generate a reverse flow across that sieve segment.

Abstract: An apparatus for circulating water in a swimming pool including a strainer that is connected to a swimming pool unfiltered intake with a pump connected to the strainer for pumping water from the strainer to a filter. The filter in turn is connected to a swimming pool filtered return for depositing the filtered water into the swimming pool. The invention includes a valve connected to the pump, strainer and filter for temporarily altering the flow of water from the swimming pool drain to the pump and back through the strainer in a direction that is opposite to the flow of water from the swimming pool drain to a waste drain. A method for cleaning the residue collected by a strainer in a swimming pool water circulation system is also included that also includes altering the flow of water from the swimming pool intake to a pump, in order that the pump may pump water in a direction opposite to the normal flow of water through a strainer to remove particles contained in the strainer.

Abstract: Circulating water for a power plant contains clams and other particles that would clog condensor tubes. Four filter units have inlets and outlets connected in parallel to a lake and the power plant, respectively. The parallel connection permits isolation of one unit for servicing while the remaining units filter the circulating water. A selected unit is isolated by blocking the inlet and outlet. A drain is opened, and backwash water is pumped to sprayers in the selected unit. Nozzles on the sprayers direct water at filter screens in the unit to wash clams and other particles collected on the screens to the drain for disposal. While the unit is thus isolated, workmen may open manholes and enter the unit interior for maintenance. The selected unit is placed online by partially opening the unit inlet to fill the unit and purge air through the open vent. When the unit is full, the vent is closed, and the inlet and outlet are fully opened.

Abstract: The invention is directed to a self-cleaning liquid filter of the type which includes a filter element through which a liquid sample is selectively passed which is taken from a stream of liquid which flows past one side of the filter element. The filter includes a housing with an inlet, a bypass outlet and a filter outlet. A filter element is mounted in the housing between the inlet and filter outlet and the inlet and bypass outlet communicate with each other through a chamber on the inlet side of the screen, the chamber extending around the inlet. The inlet is positioned in close proximity and oriented relative to the filter element so that liquid entering the housing through the inlet will hit the filter element at a right angle so that when the flow of liquid through the filter outlet is blocked all of the liquid will reflect off of the filter element and outwardly into the chamber for washing off particles on the inlet side of the filter element.

Abstract: A self-flushing, magnetic separator technique including feeding the medium to be separated to one end of a matrix in a container; collecting separated fluid from the other end of the matrix; accumulating at least one matrix volume of the separated fluid in a chamber in the container adjacent one of the ends of the matrix stopping flow to and from the matrix, trapping the accumulated fluid in the chamber; and in one embodiment introducing a pressurized drive fluid to the chamber and venting the other end of the matrix to urge the accumulated fluid to move through and flush the matrix.

Abstract: A holding tank receives waste water from a dishwasher or laundry machine having a rinse cycle and at least one wash cycle. A pump moves the waste water through a heat exchanger at the same time that the rinse cycle requires hot water from a hot water heater. The cold water feed for the hot water heater is also passed in countercurrent heat exchange relationship with the waste water to provide warmed or heated makeup water at the same time that hot water is being withdrawn therefrom. The cooled waste water from the heat exchanger may be collected in a tank and supplied to any one or more of several additional devices, such as a water cooled refrigerant compressor, a grease extraction ventilator having water contact means, a waste food grinder, etc. The ventilator and compressor may also be placed in series, while the cooling water heated in the compressor is recirculated to the heat exchanger.

Abstract: The flush-back filter according to the invention uses as supporting element for at least one filter element a support cage which is arranged firmly on the inside of the filter housing and is penetrated from the interior to the exterior by the medium to be filtered. At the interior of the support cage a lifting or rotating flush-back device is located which upon its movement passes over the slot-type windows of the support cage in succession. The slot-type windows are arranged on the support cage in several groups in such a way that the windows of the one group are offset against those of the other group(s) in the direction of movement of the flush-back device, in such a way that the windows of the one group lie at least with the webs of another group on a common plane. In this way the entire filter area is subjected to the flush-back operation during this operation only over very small surface areas, with the result that small flush-back volumes can be used and the pressure drop is slight.

Abstract: A filtering apparatus suitable for being cleaned by backwashing includes an outer housing (11) and an inner filter (13) disposed in the outer housing defining an outer annular flow passage (16) and an inner flow passage (17). The outer housing is tapered in relation to the external shape of the filter to provide a substantially uniform liquid velocity through the filter in both forward flow and backflow directions. The filter is made up of a plurality of ring-like segments (38) stacked end to end on which a filter medium (37) is mounted.

Abstract: A polyjet valve has an inlet opening into an inlet chamber normally communicating through a movable polyjet sleeve in variable amounts and in one direction with an outlet chamber having an outlet. There is a block to close the outlet and a conduit to establish backflow from the outlet chamber through the polyjet sleeve in the reverse direction and then to waste.

Abstract: This disclosure is directed to a wastewater treatment plant which includes pretreatment, aeration, final clarification and overflow/backwash chambers adapted to receive a fluid, such as home wastewater, which is to be subjected to extended aeration or aerobic digestion, the aeration chamber including an aerator having a shaft whose lower end is normally received in the fluid which is to be treated, an aerator foam deflector carried by the shaft which under abnormally high fluid levels increases the torque on the shaft and, thus, indicates abnormal operation, the final clarification chamber including a demand use filter, an overflow outlet operative should the filter become disabled, and a backwash nozzle located in the filter by reverse pumping therethrough fluid pumped from the overflow or backwash chamber.

Abstract: The apparatus comprises an enclosure divided into two compartments (13 and 14) by a partition wall (15) which has a circular row of apertures (16). Filtering elements (26) of hollow tubular shape are fixed in one (13) of the compartments by an open end on each one of the apertures (16). A rotary tubular arm (20) is mounted in the other compartment (14) and has an end which sweeps along the circle of apertures and coincides with each one of the apertures in turn. The arm has a device (21) at the rotatable end of the arm (20) for closing an aperture (16) of the partition wall (15) and the orifice (51) of the end of the arm and a suction pump (P) for applying a sudden counter-current hydraulic shock through the wall of each filtering element (26) in turn is provided.

Abstract: A rotary filter for polymers comprises an inward flow filter drum mounted in a housing and consisting of inner and outer filter barrels 7 and 6 which retain between them a cylindrical filter element 8 of wire gauze or porous sintered metal. The outer barrel has regularly spaced large openings in its outer surface which communicate through the thickness of the barrel wall and via divergent passageways with even larger openings on the inner surface of the barrel. In contrast, the inner barrel has a plurality of much smaller through openings in registry with each of the large openings. The drum is rotated by a hydraulic ram via a pawl and pinion drive to bring successive openings in the outer barrel into communication with passages 22, 23, through which accumulated solids are flashed from the corresponding areas of the filter element by the resulting reverse flow of filtrate. The filter minimizes downstream pressure fluctuations and may be used upstream of an extruder.

Abstract: Apparatus for concentrating solids from a solids/liquid mixture, particularly sludge from a waste stream/flocculating polymer mixture, includes a frusto-conically shaped drum. A solids/liquid mixture is introduced through a conduit into a large end of the rotary driven conical drum. A maximum amount of the free liquid in the mixture is released from the drum through its screen side wall near the large entrance end of the drum. The solids in the drum, after initial release of the liquid therefrom, are moved during their travel to the smaller exit end of the drum where the surface movement of the drum is slower. The resulting thickened or dewatered solids are removed from the smaller end of the drum as a formed cake or in the form of thickened sludge.

Abstract: A circular filter having separated inlet and outlet compartments such that cheese whey or the like is pumped into the vessel, is forced across a filter screen, and the filtered whey is discharged downstream for further processing. This invention incorporates (1) two rotating showers to clean the filter and (2) an outlet valve which recycles filtered whey for additional filtering and cleaning.

Abstract: A disc filter of the counter-current flow cleaning type in which the filtering body has a general cylindrical annular shape with a central cylindrical flow channel extending axially along the length of said filter body. It has annular solid filter elements spaced from each other in uniform sequence by resiliently deformable but incompressible spacer elements which allows the thickness of the slot existing between the adjacent filtration elements to be varied as a function of the axial pressure exerted on the filtering body by a support part. This variation occurs between a small thickness corresponding to the desired degree of filtration, and a maximum thickness provided to allow the cleaning of the filter by the passage in counter-current of a cleaning liquid through the thus enlarged slots. The filter elements have, in cross-section, a hydrodynamic, lenticular section, leaving between each other, a converging passage where solid materials are retained.

Abstract: A filtering apparatus suitable for being cleaned by backwashing includes an outer housing (11) and an inner filter (13) disposed in the outer housing defining an outer annular flow passage (16) and an inner flow passage (17). The outer housing is tapered in relation to the external shape of the filter to provide a substantially uniform liquid velocity through the filter in both forward flow and backflow directions. The filter is made up of a plurality of ring-like segments (38) stacked end to end on which a filter medium (37) is mounted.

Abstract: A filtering apparatus suitable for being cleaned by backwashing includes an outer housing (11) and an inner filter (13) disposed in the outer housing defining an outer annular flow passage (16) and an inner flow passage (17). The outer housing is tapered in relation to the external shape of the filter to provide a substantially uniform liquid velocity through the filter in both forward flow and backflow directions. The filter is made up of a plurality of ring-like segments (38) stacked end to end on which a filter medium (37) is mounted.

Abstract: Waste water is led into a container (1) through an inlet (4) at the top. A connection (20) between the inlet (4) and an outlet (21) having a check valve (22) comprises adjacent to the inlet (4) two inverted frusto-conical hollow bodies (24, 25) which are directly connected to each other. The connecting surface between the two hollow bodies (24, 25) is formed as a coarse screen (26). A round fine screen (30), which diverges downwardly, surrounds the hollow bodies (24, 25). Heat exchangers (31) are located in the space between the fine screen (30) and the wall (2) of the container (1). An outlet (5) terminates at the bottom of the container and connects with a riser (6) and via a bend (7) with the sewerage conduit (8). Through the coarse screen (26) the waste water reaches the container, and the heat can reach the heat exchangers (31) through the fine screen (30 ), so that practically uncontaminated water is present at the heat exchangers, and the need for cleansing is substantially diminished.

Abstract: A method and apparatus for removing dissolved solids from a liquid which utilizes the technique of reverse osmosis (RO). The liquid to be treated is directed into a pressure vessel which contains a plurality of filter elements positioned therein. The filter elements have hollow RO fibers wound around foraminous center cores such that the liquid flows in a direction from the outside of the filter elements towards the center cores. The pure permeate liquid passes into the center bores of the fibers and the concentrate liquid passes into the center cores of the elements.The method and apparatus provide for the backwashing of the filter elements when they become fouled. Further, an outer filter septum may be applied around the hollow RO fibers of the elements to remove particulate matter which would otherwise foul the hollow RO fibers.

Abstract: A lymphapheresis or lymph filtration system is disclosed for removing lymph from a patient, separating the lymph into a liquid fraction and a cellular component fraction and returning the liquid fraction to the patient. The system includes an input pump to pump lymph from the patient into a filtration cell having a membrane which filters the lymph into fractions. The liquid fraction is removed from the cell by a reversible pump and is returned to the patient. As the membrane becomes plugged the reversible pump is reversed to backflush the membrane to return it to a high filtration rate. The cellular component fraction which includes lymphocytes is disposed of.

Abstract: The method and apparatus for filtering a liquid including a filter vessel divided into an upper filter compartment and a lower plenum compartment. An external vessel is positioned at or below the elevation of the tops of the filter element fittings in the plenum compartment. A pressurized gas is supplied to the upper portion of the external vessel forcing backwash liquid from the external vessel into the lower portion of the plenum compartment backwashing filter elements within the filter compartment.

Abstract: The invention relates to a filtration apparatus with an upper casing part and a base part, each provided with a fluid chamber and an inlet or outlet respectively, for holding a flat filter plate cut to size which is enclosed between a permeable filter support associated with at least one casing part, and the other casing part, in which structure the two casing parts with inclusion of the flat filter plate cut to size are in the edge area sealed against each other in a leakproof manner and are connected by detachable tightening means.

Abstract: A disc-type filter, having a filter housing and contained therein a stack of slightly spaced apart axially moveable annular filter plates slidably interconnected to each immediate adjacent plate by three symmetrically and uniformly placed two-headed rivets which provide a predetermined and uniform spacing between the plates when the plates are moved apart for cleaning by reverse flushing. An actuation rod allows selective enlargement of the spaces between the plates, and holds the plates in their spaced apart cleaning position. The stack of plates is held in axial alignment immediately over an input port by guide bars which slidable engage the periphery of the plates. The plates and filter are constructed to permit use of one plate in any position in the stack, and the plates have an annular flange to divert fluid flow to improve cleaning and provide a pre-filtering for larger particulate matter.

Abstract: A high transfer pressure device, and method, especially adapted for continuously conveying hard particulate material such as coal; and a screen specifically for use in such conveying. The high pressure transfer device includes a pocketed rotor containing a pair of diametrically through-going pockets perpendicular to each other, a housing enclosing the rotor and having four ports spaced around the periphery thereof, and a screen operatively associated with the rotor or the ports for screening out particles above a predetermined size that are conveyed in liquid passed through the device. Preferably the screen is associated with one of the ports of the housing and fluid injection nozzles are associated with the screen for injecting liquid under pressure toward the screen to effect dislodgement of any particles that may be lodged in the screen and thereby prevent damage to the screen. The operation of the fluid injection nozzles is timed to the rotation of the rotor.

Abstract: A filter cone fixed to the bottom of a washing machine basket includes a plurality of closely spaced rigid teeth in a circumferential row extending outwardly and upwardly to divide the tub into first and second chambers for filtering laundry liquid during a washing cycle and for preventing sediment and debris from returning into the basket during a direct-into-spin portion of the wash cycle. The reverse flow of water through the filter teeth during the drain portion of the washing cycle effects self-cleaning of the teeth.

Abstract: A device for removing foreign particles from a source of fluid under pressure which is adaptable to be connected to a faucet or the like. It comprises one or more screens which are provided to collect the foreign particles which might include small stones, calcium deposits and the like, such that the particles cannot pass through the mesh of the screen. Such screens are mounted on a rotatable member having an exteriorly accessible handle whereby the rotatable member and screens thereon can be rotated at least ninety degrees and preferably one hundred eightly degrees so that the force of the fluid under pressure cleans off the screen and enables it to be used again to collect or intercept other additional foreign particles.

Abstract: A filter device comprising a tubular housing with an inlet for the fluid to be filtered in one end of the housing, an outlet for filtrate in the opposite end of the housing and a filter tube mounted inside the housing and extending essentially in the axial direction of the tubular housing. At least part of the filter tube wall forms the filter surface. One end of the filter is openly connected to said inlet, whereas the other end is closed so that an annular feed conduit is formed between the housing and the filter tube. A first valve means is arranged inside the filter tube to shut off the filter tube, during cleaning periods, thereby dividing the filter tube and the filter surface into an upstream part and a downstream part, and forcing the entire filtrate stream to pass through said upstream part of the filter surface into the filtrate conduit.

Abstract: A system for filtering liquids, such as coolant liquid from process machinery. The system includes an improved liquid storage tank having a partition dividing the tank into a clean tank for receiving clean liquid from a filter for return to the process machinery, and a dirty tank for receiving process or dirty liquid from process machinery. The storage tank further includes a second partition forming a blowdown chamber and a recirculation chamber below the blowdown chamber, the two chambers being coupled together by a valve which can be opened and closed depending upon the cycle of operation of the system. The recirculation chamber is coupled by a filter pump to the inlet of the filter. The filter has a return line to the clean tank and a blowdown line to the blowdown chamber. The blowdown chamber has a conical bottom and the recirculation chamber has a sidewall provided with tangential inlet ports communicating with the dirty tank.

Abstract: A filtering arrangement of thermoplastics extruding apparatus has a rotatable cylindrical screen unit through which material flows radially inwards and is discharged axially and an outlet aperture for impurities which are washed from the screening unit by reverse flow, i.e. radially outward flow, of part of the filtered material. The outlet aperture for the impurities is variable in cross-section by moving an arcuate segment about the axis of the cylinder to control the extent of reverse flow washing.

Abstract: A strainer is provided for removing particulate debris from a fluid passing therethrough. The strainer is primarily of the automatic type having a hollow body, a cover, a strainer element and a backwash arm assembly for cleaning the strainer element. The strainer element is a cylindrical, convoluted screen having encapsulating end caps positioned at either end. The end caps and thus the strainer element are retained so as to avoid rotation in seal rings, one of which is connected to the cover and the other of which is detachably connected to the terminus of the backwash arm. The strainer element is a structural member capable of withstanding the loads imposed on it by the fluid.

Abstract: A dishwasher structure having a centrifugal pump for providing dishwashing liquid to a spray arm thereof. The swirling motion of the dishwashing liquid effected by operation of the pump is utilized to divert a portion of the liquid to an accumulator wherein soil material is collected from the liquid. The cleansed liquid is returned to the pump chamber to be repumped with additional dishwashing liquid. A drain is provided for draining the dishwashing liquid and collected soil at the end of the dishwashing cycle and is controlled by a pressure-responsive drain valve which is operated by differing pressure conditions automatically during dishwashing and drain cycles respectively.

Abstract: A strainer of the self-cleaning type includes a strainer element capable of removing matted debris by backwashing. The strainer element comprises a plurality of stacked annular strainer plates maintained in spaced relationship to form straining passages wherein the passages are substantially greater in depth than height. Protruding surfaces of the strainer element form vertically aligned compartments along its upstream side. The compartments collect the debris. A rotating backwash arm or arms are provided which may carry at least one cutting blade. The blade cuts matted debris extending between compartments into sections as it passes over these protruding surfaces and these sections are removed by backwashing.

Abstract: A backwashable filtering device comprising a housing, a main filter in the housing, an inlet for receiving liquid into the housing and an outlet for discharging liquid from the housing. A rotatably mounted spraying member is disposed in the main filter which is preferably cylindrical in shape for receiving liquid and discharging it against the inner surface of the filter to backwash and cleanse the filter. Filtering passage is defined in the housing between the inlet and the outlet for directing water against an outer surface of the main filter for the purpose of filtering the water. Valves are provided in the housing associated with the main filter for selectively directing liquid toward the opposite sides of the main filter for the purposes of filtering and backwashing respectively.

Abstract: A coalescing/filtration media composed of yarn-like material held together during normal operation but loosened during backwash to allow "strumming" or vibrating to help loosen media-clogging material, and an armature arrangement by which a cylindrical assembly of yarn segments can be tightened in a helical fashion to perform as filtration/coalescing media or, during backwash, can be loosened to promote the dislodging of clogging material.

Abstract: A self-cleaning filter assembly for removing solids from an incoming liquid to be filtered. A filter element is fixed substantially coaxially within a housing and spaced from the peripheral wall thereof by an annular solids collection space in turn communicating with a solids outlet. An inlet introduces pressurized liquid to be filtered circumferentially into the solids collection space. A shower assembly rotates coaxially within the filter element and includes an eccentric portion having jets distributed along the length of the filter element and aimed outward close to the inner surface of the filter element. Backwash liquid enters the rotating shower assembly under pressure for continuously pushing solids off the outer surface of the filter element as the shower assembly circumferentially advances in the housing. Filtrate from inside the filter element passes through a filtrate outlet extending from the housing.

Abstract: An apparatus for the filtering of a fluid in which a filter-aid agent of a particulate or fibrous character is floated onto and deposited upon a support fabric in a fluid. The medium to be filtered is then passed through the filter layer formed by this filter aid. The fabric divides the filter chamber into two compartments both of which are flushed with washing liquid which is discharged from the upstream compartment after back-washing through the fabric. During the filtration, a loss of the purified filtrate and a mixture with nonfiltered medium is precluded in that both compartments, after the filtering and cleaning phases, are completely discharged of fluid. The back-washing of the fabric is effected with another fluid. The complete discharge is effected in the direction of flow of each medium through the respective compartment.

Abstract: A backwashable filtering device is described including a backwash nozzle and means for effecting relative movement between it and the filter body, and further including a valve assembly movable to open or close the passage between the filter body and the housing outlet in response to low pressure conditions, thereby to maintain the pressure for backwashing the filter body via the nozzle.Also described is the provision of a sleeve axially movable to open or close a passage between the housing inlet and the filter body, which sleeve is movable either manually or automatically in response to pressure or other specified condition.

Abstract: A high efficiency domestic furnace incorporates means for separating and neutralizing flue gas condensate. Acidic condensate from the flue gas products of combustion is neutralized by contact with neutralizing material in a housing through which the condensate is flowed. The use of the neutralizer in connection with a high efficiency domestic furnace permits discharge of the condensate directly to the household drain. The neutralizer is arranged to be self-flushing and defines a serpentine, series flow path and is arranged to discharge the neutralized condensate as a result of the entry of additional acidic condensate at its inlet.

Abstract: An in-line apparatus for separating oversize particles from a pressurized fluid slurry which comprises:a rigid, hollow body member capable of withstanding the pressure of the fluid slurry, the body member having a valved slurry inlet port and a slurry outlet port, each port adapted to mate with slurry conduit means;a washer access port opposite from and in axial alignment with the slurry outlet port;a hollow, open-ended screen assembly fixedly mounted within the body member between and in axial alignment with the slurry outlet port and the washer access port;a valved oversize particle discharge port at the lowermost end of the body member adapted to mate with oversize particle conduit means; andretractable backwasher means externally mounted on the body member in axial alignment with the washer access port and the screen assembly, where the backwasher means comprises a fluid discharging spray head adapted to pass axially through the interior of the screen assembly, whereby a pressurized backwashing fluid is d

Abstract: A filter unit comprises an outer casing defining a vertical-axis first chamber having a liquid inlet and a normally-closed discharge valve at its lower end and a second chamber defined by upper and lower end walls, a perforated cylindrical wall located within the first chamber and covered by a filter element and a non-perforated cylindrical wall having a lower portion coaxial with, and within the perforated wall and an upper portion projecting above the first chamber and having an outlet for liquid filtered through the filter element. A piston is slidable within the non-perforated wall to force liquid through the filter element to cleanse the latter when it becomes clogged, the piston being connected to open the discharge valve to discharge the particle-containing liquid from the first chamber. A non-return valve in a duct connected to the outlet allows air into the space above the piston to facilitate its descent.

Abstract: A backwashable filtering device is described comprising a housing having a filter body and a backwash nozzle disposed therein, characterized in that the backwash nozzle is fixed with respect to the housing, the filter body is rotatably mounted with respect to the backwash nozzle, and the filtering device further includes a rotor and gear drive means rotating the filter body by the energy of the backwash fluid flowing through the nozzle.

Abstract: In a rotary drum vacuum filter, the drum sectors are connected by conduits to apertures in a rotary valve member on the drum which is opposed to a fixed valve member. The valve members thus control supply of vacuum (to cause suction filtering) and pressurized gas (to blow the cake of filtered material from the filter) to the drum sectors as the drum rotates. In order to eliminate the time delay between suction and blowing which is needed in order to allow the conduits to purge, another group of conduits is provided, having one-way valves adjacent their connection to the drum surface; this group is used only for blowing. The different groups of conduits are connected to apertures of the rotary valve member at different radial distances from the axis of rotation.

Abstract: In a rotary drum or disc filter having circumferentially distributed cells in constant communication through open outlets with a common vacuum chamber, which may be the interior of the drum, or part of that interior, or a separate chamber rotating together with the filter. In a position of each cell where filter cake is to be blown off, a jet of compressed air or steam is injected into the respective outlet through a nozzle which combines with the outlet to form an ejector pump (jet pump).